Clock input buffers which buffer a TTL level clock input signal into an MOS level clock output signal are commonly required in electronic circuits. A typical application is in high speed microprocessor circuits where both speed and power consumption are important considerations. Previous buffer circuits which provide a continuous clock signal commonly utilize inverters connected in series. Such circuits have several stages of delay and consume excessive power at TTL voltage levels. Other known clock buffer circuits which are relatively fast in speed have the disadvantage of excessive power consumption.